Abstract: A sweetener composition is provided, formed with natural plant extracts including Luo Han Guo fruit extract and sweet stevia extract, and neohesperidin dihydrochalcone (NHDC) as raw materials at a scientific and sound mixing ratio such that the disadvantage of having a strong aftertaste of water is eliminated, and the Chinese herbal medicine taste of the Luo Han Guo fruit and the bitter aftertaste of stevia sugar are effectively shielded. The sweetener composition successfully removes the Chinese herbal medicine taste of Luo Han Guo fruit and the bitter aftertaste of stevia sugar while fully exerting the herbal fresh and sweet taste of the Luo Han Guo fruit extract and the sweet stevia extract, and perfectly combines the sweet aftertaste of mogrosides, so that the sweet taste is maintained and the taste is good, and the sweetener composition of the present invention is well accepted by consumers.

Abstract: A sealed tube neutron generator (&agr;-STNG) incorporates an internal associated-&agr; detector for well logging. The &agr;-STNG comprises a gas-tight envelope, a Penning ion source, a gas supply, an accelerating electrode and a target as those in conventional STNG; and further comprises a special target chamber, an ion leading out and focusing assembly, an annular associated -&agr; particle detector mounted in the target chamber, a gas absorber, and a collimator for &agr;-particles. The &agr;-STNG can be employed within a nuclear Carbon/Oxygen Well Logging Apparatus which adopts the Associated Particle and Time of Flight Approach for collecting data to satisfy the special requirements of well logging, to expel the adverse effect resulted from cased hole materials and thermal neutrons capture for increasing the precision of carbon/oxygen ratio logged. When the carbon window is 3.17 to 4.65 Mev and the oxygen window is 4.68 to 6.